Searching databases for journal articles is a bit more challenging than using tools such as Google or Bing. The good news is that you have a lot more control over how you design the search. This also means you should get better, more targeted results.
Before you start searching, try focusing your topic by writing a one sentence research question. For example: What influence do different groups wield in Iranian politics?
Identify the main ideas in your research question.
groups within Iran
Boil the statement down to keywords, or the most important elements of your issue. EX: Iran, identity politics, groups
Use an asterisk to find variations of a word. EX: iran* will find iran, iranian, iranians
Then, separate the keywords with the "and" and "or" connectors EX: iran* and identity politics or group identity
The above search strategy in the Political Science Complete database will look like this. Note that I changed "Select a Field" to "SU Subjects" so only the index terms for this article are searched.
You can also limit your search to "peer reviewed" publications so you search only the academic literature.
This search retrieved 16 peer reviewed citations.
If I add particular groups to the search, my first line looks like this and retrieved 223 peer reviewed citations:
identity politics or group identity or azerbaij* or kurd* or sunni* or shia or shiites